Abstract: The present invention relates to an adsorption-type air drying system, of which the object is to simplify the flow paths of the system, reduce the number of the components such as a valve intricately controlled according to the state of operation, and decrease the cost for constructing the system. Furthermore, the object of the present invention is to provide an adsorption-type air drying system which may be used under various pressure conditions, and smoothly operated regardless of the pressure change of the system by means of a structure compensating for the pressure loss generated during non-purge operation.

Abstract: The present invention relates to a method of protein synthesis and, more particularly, to a method of effective protein synthesis by regulating the expression of a protein in a host cell, wherein said host cell is transformed with an expression vector comprising a promoter as well as a DNA fragment for a gene that encodes a desired protein, wherein said promoter has an inductive activity for transcription during the resting stage of cell growth and also the induction of said protein expression can be controlled by varying culturing conditions.